Crews found a man's body inside the burned out car that sparked a five-acre fire near Crockett close to the Carquinez Straight Regional Shoreline Park.
So far, investigators don't know why the victim's car ran off the road, but they say there were two people inside when it crashed.
The second person was not seriously hurt. Four different agencies battled the blaze.
"No structures were endangered, nor were they threatened," said CAL FIRE Batallion Chief Mike Marcucci. "We did have to shut down the rail line, though, for firefighter safety, and we do have power lines down. That may be interrupting some customers' power."
A photo sent anonymously to UReport shows just how far away the smoke could be seen Thursday afternoon.